This set of bookends (taking the form of an eagle statue and a lion statue) allow two people to switch bodies when the heads of the bookends are swapped. The only way to reverse the process is to put the heads on the proper statue. If the heads are not swapped back in time the users will merge, causing one person to appear then the other (similar to Dr. Jekyll and Mr. Hyde). If left unchecked, the people will keep swapping until they overlap each other causing both explode, due to the impossibility of two people occupying the same point in space. If the bookends are seperated, one of the bookend's eyes will glow and then turn in the direction of the other after being set it down.
Robert Louis Balfour Stevenson was a Scottish novelist who wrote Treasure Island, Kidnapped, and The Strange Case of Dr. Jekyll and Mr. Hyde. He died in 1894, at the age of 44.